CN105708567B

CN105708567B - Biased pivoting sliding orthodontic bracket

Info

Publication number: CN105708567B
Application number: CN201510943965.9A
Authority: CN
Inventors: 史丹利·S·黄
Original assignee: Ormco Corp
Current assignee: Ormco Corp
Priority date: 2014-12-19
Filing date: 2015-12-16
Publication date: 2020-02-28
Anticipated expiration: 2035-12-16
Also published as: US9943383B2; RU2015154492A; US20160175073A1; EP3034030A1; JP2016116861A; CN105708567A; KR20160075354A; RU2708205C2; JP6681706B2; RU2015154492A3

Abstract

An orthodontic bracket includes a bracket body and a ligating slide. The bracket body includes a bore and an archwire slot. The ligating slide is slidable relative to the archwire slot between an open position and a first closed position, and rotatable relative to the archwire slot to a second closed position. The orthodontic bracket further includes a spring coupled to the ligating slide and slidable within the hole. The lashing slide defines a first height from the base surface having a first value and, in the second closed position, the lashing slide defines a second height from the base surface. The bracket body includes a sliding support having at least one wing extending laterally therefrom. The thickness of the wings becomes gradually smaller. The slide support defines a pivot point about which the ligating slide may rotate.

Description

Biased pivoting sliding orthodontic bracket

Cross Reference to Related Applications

This application claims priority to U.S. provisional application 62/094,451 filed on 12/19/2014, which is hereby incorporated by reference in its entirety.

Technical Field

The present invention relates generally to orthodontic brackets and, more particularly, to self-ligating orthodontic brackets having a movable closure member.

Background

Orthodontic brackets represent an important component in all orthodontic treatments aimed at improving a patient's bite. In conventional orthodontic treatment, an orthodontist or assistant affixes brackets to a patient's teeth and engages an archwire into the slots of each bracket. The corrective force exerted by the archwire will force the teeth to the correct position. Conventional ligatures, such as small elastomeric O-rings or pure wires, are used to retain the archwire within the slots of the respective brackets. Because of the difficulties encountered with the use of a single ligating member on each bracket, self-ligating orthodontic brackets have been developed which retain an archwire within a slot of the bracket without the need for a ligating member by relying on movable parts or members, such as latches or slides.

While such self-ligating brackets have generally been successful in achieving their intended purpose, certain disadvantages remain. For example, in some cases, such as near the end of orthodontic treatment, control of tooth rotation may be problematic. While there are some factors that contribute to reduced rotational control, it is believed that one primary reason is the loose fit of the archwire within the archwire slot of the bracket when the movable member is closed. When the movable member is closed, the bracket body and the movable member together form a closed lumen that captures the archwire. During orthodontic treatment, a tight fit between the inner lumen and the archwire is considered important to achieve excellent rotational control.

Some factors that affect the tight fit between the archwire and the archwire slot when closing the movable member include, for example, tolerances in the manufacturing process that forms the bracket body and the movable member. When the orthodontic bracket is assembled, various tolerances may "stack up" such that a relatively loose fit is provided between the archwire and the closed cavity provided by the bracket body and the movable member. As mentioned above, this loose fit is believed to reduce the ability to control tooth rotation.

Furthermore, in order to move the movable member relative to the bracket body between the open and closed positions, some clearance between the bracket body and the movable member is necessary. In other words, some tolerances in the manufacturing process typically provide clearance. However, these tolerances add up to provide a cavity that may vary significantly in labial-lingual dimensions between brackets, possibly providing a relatively weak fit with the archwire in some cases.

Thus, while self-ligating brackets have been generally successful, manufacturers of such brackets are continually striving to improve the use and function of the brackets. In this regard, there remains a need for self-ligating brackets that provide improved rotational control during orthodontic treatment, such as during the end stage thereof.

Disclosure of Invention

To address the shortcomings of existing orthodontic brackets, an orthodontic bracket for coupling an archwire with a tooth is provided that includes a bracket body and a ligating slide. The bracket body includes an aperture and an archwire slot for receiving an archwire therein. The ligating slide is slidable relative to the archwire slot between an open position in which an archwire may be inserted into the archwire slot and a first closed position in which the ligating slide may retain the archwire within the archwire slot. The ligating slide is rotatable relative to the archwire slot to a second closed position wherein the ligating slide retains the archwire within the archwire slot. The second closed position is different from the first closed position.

In a particular embodiment, the second closed position defines a lip-to-tongue height between the ligating slide and the archwire slot base that is greater than a lip-to-tongue height between the ligating slide and the archwire slot base in the first closed position. The ligating slide may be rotatable relative to the bracket body to an angle that exceeds the normal tolerance stack-up of existing orthodontic brackets. The orthodontic bracket further includes a spring coupled to the ligating slide and slidable within the aperture.

In a particular embodiment, the ligating slide may be rotatable to an angle between the first closed position and the second closed position that is greater than about 5 ° to about 20 °. In a particular embodiment, the ligating slide may be rotatable to an angle between the first closed position and the second closed position, the angle being from about 10 ° to about 20 °.

In a specific embodiment, the archwire slot includes opposing slot faces extending from a base face, and in the first closed position, the ligating slide defines a first height from the base face having a first value, and in the second closed position, the ligating slide defines a second height from the base face that is at least 0.002 inch greater than the first value.

In a particular embodiment, the bracket body includes a sliding support having at least one wing extending laterally therefrom. The thickness of the wings tapers along their length. The slide support defines a pivot point about which the ligating slide rotates between the first closed position and the second closed position. The tapered wings define a first gap between the slide support portion and the ligating slide in the first closed position and a second gap between the slide support portion and the ligating slide in the second closed position. In a particular embodiment, the lashing slide includes a uniformly sized groove within which the wing is located during sliding of the lashing slide.

In a particular embodiment, in the first closed position, a gap exists between the recess and the wing. In a particular embodiment, the groove defines a shoulder that contacts the wing in the second closed position.

In a particular embodiment, the bracket body includes a support surface and the ligating slide includes a sliding surface that faces the support surface when the ligating slide is in the first closed position, the support surface and the sliding surface contacting at a pivot point when the ligating slide is rotated to the second closed position, the support surface and the sliding surface forming an angle therebetween of greater than about 5 °.

In a particular embodiment, the pivot point is located at a peripheral edge of the support surface distal from the archwire slot.

In a particular embodiment, the resilient member applies a biasing force to the ligating slide in each of the first and second closed positions.

In a particular embodiment, the ligating slide does not rotate about the elastic member.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the detailed description given below, serve to explain various aspects of the invention.

FIG. 1 is a perspective view of an orthodontic bracket attached to a tooth showing a slide in a closed position according to one embodiment of the invention;

FIG. 2 is a perspective view of the orthodontic bracket of FIG. 1, showing the slide in an open position;

FIG. 3 is an exploded view of the orthodontic bracket shown in FIG. 2;

FIG. 4 is an elevation view of the orthodontic bracket body shown in FIG. 3;

FIG. 5 is a side view of the orthodontic bracket body shown in FIG. 3;

FIG. 5A is an enlarged view of a portion of the orthodontic bracket shown in FIG. 5;

FIG. 6 is a perspective view of the slider shown in FIG. 3;

FIG. 7 is a rear view of the slider shown in FIG. 3;

FIG. 8 is a side view of the orthodontic bracket shown in FIG. 1;

FIG. 9A is a cross-sectional view of the orthodontic bracket taken along section line 9A-9A of FIG. 2, depicting the slide in the open position;

FIG. 9B is a cross-sectional view of the orthodontic bracket taken along section line 9A-9A of FIG. 2, depicting the slide in a position between the closed position of FIG. 1 and the open position of FIG. 2;

FIG. 9C is a cross-sectional view of the orthodontic bracket taken along section line 9A-9A of FIG. 2, depicting the slide in a position between the closed position of FIG. 1 and the open position of FIG. 2, and different from the position shown in FIG. 9B;

FIG. 9D is a cross-sectional view of the orthodontic bracket taken along section line 9A-9A of FIG. 2, depicting the slide in the closed position;

FIG. 10 is a cross-sectional view of the orthodontic bracket shown in FIG. 8 taken along section line 10-10;

FIG. 11 is a cross-sectional view of the orthodontic bracket of FIG. 8 as taken along section line 11-11 of FIG. 10;

FIG. 11A is a cross-sectional view of the orthodontic bracket of FIG. 8 as taken along section line 11A-11A of FIG. 10;

FIG. 12 is a cross-sectional view of the orthodontic bracket of FIG. 8 taken along section line 11-11 of FIG. 10, showing the slide in another closed position; and

FIG. 12A is a cross-sectional view of the orthodontic bracket taken along section line 11A-11A in FIG. 10, depicting the slider pivoted outward as shown in FIG. 12.

Detailed Description

Referring now to the drawings, and in particular to fig. 1 and 2, an orthodontic bracket 10 includes a bracket body 12 and a movable closure member coupled to the bracket body 12. In a particular embodiment, the movable closure member includes a slide, such as a ligating slide 14, slidably coupled with the bracket body 12. The bracket body 12 includes an archwire slot 16 formed therein, the archwire slot 16 being configured to receive an archwire 18 (shown in phantom) to apply a corrective force to the tooth. The ligating slide 14 may be slidable between a closed position (fig. 1) wherein an archwire 18 is retained within an interior cavity defined by the archwire slot 16 and the ligating slide 14, and an open position (fig. 2) wherein the archwire 18 may be inserted into the archwire slot 16. It is also possible to move the ligating slide 14 in an outward direction relative to the archwire slot 16 to a second closed position, which may be generally perpendicular to the sliding motion of the ligating slide 14. The second closed position may be a fixed position predetermined by the bracket body 12 and the ligating slide 14. The second closed position may also define an inner cavity to retain the archwire 18 therein. However, unlike a clevis or other flexible retainer, observations during normal orthodontic treatment have found that ligating slides 14 according to embodiments of the invention do not significantly bend when loaded. The bracket body 12 and ligating slide 14 together form an orthodontic bracket 10 for corrective orthodontic treatment.

In addition to the above, the orthodontic bracket 10 further includes a spring coupled to the ligating slide 14, the spring configured to engage at least a portion of the bracket body 12. As explained in more detail below, in one embodiment may include a resilient member in the form of a tubular pin 20 (shown in FIGS. 1 and 2), the tubular pin 20 at least partially providing a force in the direction of sliding or translational movement for biasing the ligating slide 14. The tubular pin 20 may also or alternatively bias the ligating slide 14 toward the archwire slot 16. Although the spring is shown here as a tubular pin, the invention is not limited to this particular configuration and other springs may be configured in accordance with the invention disclosed herein. It is believed that the structural features of the orthodontic bracket 10 are utilized to provide the biasing force, as described in greater detail below, to reduce the effect of tolerances of the archwire slot 16 in combination with other tolerances. By limiting the overall effect of tolerances, it is possible to more accurately know the working dimension of the archwire slot 16. This enables the clinician ultimately to more accurately predict and control tooth movement with orthodontic brackets. It will be appreciated that improved clinician control over tooth movement can relatively reduce treatment time for a particular patient.

In combination with other structural features of the bracket body 12 as described in detail below, the resilient member 20 enables the bracket 10 to actively ligature an archwire having a height dimension greater than the height (e.g., lip-lingual height) of the archwire slot 16. Thus, the clinician may select an oversized archwire and actively ligature the archwire with the slide 14 during treatment. This may improve the requirements for rotational control that are often desired during the final stages of orthodontic treatment and may allow orthodontic treatment to be completed in a faster time than self-ligating orthodontic brackets that can only be passively ligated.

Unless otherwise indicated, the frame of reference used in describing the orthodontic bracket 10 herein is attached to the labial surface of the anterior mandibular teeth. Accordingly, terms used herein to describe the bracket 10, such as labial, lingual, mesial, distal, occlusal, and gingival, are all relative to the chosen frame of reference. However, embodiments of the present invention are not limited to the selected frame of reference and descriptive terms, and the orthodontic bracket 10 may be used with other teeth and other orientations within the oral cavity. For example, it is also within the scope of the present invention that the bracket 10 may be coupled to the lingual surface of a tooth. One of ordinary skill in the art will recognize that the descriptive terms used herein should not be directly applied when the frame of reference is changed. However, the embodiments of the present invention are intended to be independent of position and orientation within the oral cavity, and the relative terms used to describe the embodiments of the orthodontic brackets are intended merely to provide a clear description of the embodiments in the drawings. Thus, the relative terms lip, tongue, mesial, distal, occlusal, and gingival should not limit the present invention at all to a particular position and orientation.

When mounted to the labial surface of a tooth T on a patient's mandible (labeled in FIG. 1) and referring particularly to FIG. 3, the bracket body 12 has a labial side 22, an occlusal side 24, a gingival side 26, a mesial side 28, a distal-medial side 30, and a lingual side 32. The lingual side 32 of the bracket body 12 is configured to be secured to the tooth in any conventional manner, for example, by a suitable orthodontic cement or adhesive, or by a band of tape around the adjacent tooth. In one embodiment shown in fig. 1-3, lingual side 32 may further have a pad 34, the pad 34 defining an engagement base secured to the surface of tooth T. The pad 34 may be coupled to the bracket body 12 as a separate part or element, or alternatively, the pad 34 may be integrally formed with the bracket body 12. Further, the pad 34 may be specially shaped to accommodate the surface of a particular tooth. Thus, the cushion 34 may have a number of configurations different from that shown in fig. 1-3. It should be understood that embodiments of the present invention are not limited to any particular configuration of the cushion 34.

Referring to fig. 1 and 2, the bracket body 12 includes a base surface 36 and a pair of opposed slot surfaces 38, 40 projecting labially from the base surface 36, the base surface 36 and the slot surfaces 38, 40 together defining the archwire slot 16, the archwire slot 16 being extendable in a mesial-distal direction from the mesial side 28 to the distal side 30. The base surface 36 and the slot surfaces 38, 40 are substantially encapsulated or embedded within the material of the bracket body 12. Although not limited thereto, the bracket body 12 and/or ligating slide 14 may be made of a ceramic, such as the ceramics described in commonly owned U.S. patent No. 8,585,398 issued on 11/9/2013 and U.S. publication No. 2010/0173256 issued on 7/8/2010, which publications are hereby incorporated by reference in their entirety.

As shown in FIG. 3, in a particular embodiment, the bracket body 12 further includes a slide support 42, the slide support 42 being configured to receive the ligating slide 14 therein. The slide support 42 may protrude generally labially from the cushion 34 or be positioned generally perpendicular to the cushion 34. The slide support 42 may also extend generally perpendicular to the archwire slot 16. The slide support 42 terminates at its portion closest to the lip in a support face 50 for sliding engagement of the ligating slide 14 over at least a portion of the translational movement of the ligating slide 14 from the open position to the closed position. In intra-labial application (shown in fig. 1), the support surface 50 is positioned gingival-side of the archwire slot 16 and extends longitudinally in a generally occlusal-gingival direction.

Referring now to fig. 4 and 5, in one embodiment, the slide support 42 has a generally T-shaped configuration (as best shown in fig. 4) with opposed mesial and distal projections or

wings

44, 46 extending from a central portion 48. In the illustrated construction, the thickness of the proximal and distal

central wings

44, 46 gradually decreases in the occlusal-gingival direction (as best shown in fig. 5 and 5A). Specifically, with respect to the

wings

44, 46 shown having progressively smaller thicknesses, the thickness of each

wing

44, 46 decreases uniformly from the gingival-most edge of the sliding support 42 to the occlusal-most edge. By way of example only, the thickness T1 of each

wing

44, 46 at the gingival-most edge of the sliding support 42 is approximately 0.015 inches, while the thickness T2 of each

wing

44, 46 at the occlusal-most edge of the sliding support 42 is approximately 0.010 inches. Thus, the thickness is reduced by about 30% over the gingival-occlusal length of the mesial and

distal wings

44, 46. Generally, the varying thickness of each

wing

44, 46 allows the slider 14 to be able to move outwardly (e.g., labially) relative to the base 36 of the archwire slot 16 when the slider 14 is in the closed position shown in fig. 1, as will be described in greater detail below.

With continued reference to FIG. 5, in one embodiment, the support surface 50 is angled relative to the base surface 36. Specifically, the bearing surface 50 may be adjusted to be inclined toward the archwire slot 16 such that the thinnest portion of the

wings

44, 46 are closest to the archwire slot 16. It should be understood that the

wings

44, 46 may be tapered in the opposite direction as shown in the figures and provide the functions described below.

Fig. 5 and 5A also show that the slide support portion 42 includes a hole 52, and the hole 52 is formed as a through hole in the mesial-distal direction. The aperture 52 may be positioned such that the longitudinal axis of the elastic member 20 is generally parallel to the archwire slot 16 and extends in the mesial-distal direction. In one embodiment, the aperture 52 is a generally asymmetric aperture relative to a plane perpendicular to the sliding direction indicated by arrow 54 shown in FIG. 2. The aperture 52 may be described as having an asymmetrical configuration.

As will be described in greater detail below, the aperture 52 is configured to slidingly engage the resilient member 20 to bias the ligating slide 14 in a particular direction when the ligating slide 14 is in the closed position. For example, as shown in FIG. 1, when the slider 14 is in the closed position, the aperture 52 combines with the resilient member 20 and the slider 14 to create a resultant force on the slider 14 to hold it in the closed position. In addition to the other forces described below, this resultant force must be overcome before the slider 14 can be moved from the closed position, or in the gingival direction according to fig. 1, or towards the open position. The resultant force maintains the slider 14 in a fixed, more stable position relative to the bracket body 12, thereby maintaining a more consistent labial-lingual archwire slot size. Advantageously, the tolerance of the overlap in the lip-tongue direction is reduced or eliminated.

As shown in fig. 5 and 5A, the aperture 52 may include a first lobe 56 proximate the gingival side 26. For illustration only, the first lobe 56 may define a generally circular perimeter along a portion of the bore 52. The lobe 56 may be defined by an axis 58 and a radius R1. The aperture 52 may further include a second lobe 60 closest to the archwire slot 16, that is, the second lobe 60 is positioned on the occlusal side of the first lobe 56. Similar to the first lobe 56, the second lobe 60 may be defined by a generally circular perimeter having an axis 62 and a radius R2.

In a particular embodiment, the bore 52 includes a mid-portion 64, the mid-portion 64 being positioned between and connecting the first lobe 56 and the second lobe 60. The mid portion 64 may include a first section 66, the first section 66 being tangential to the first lobe 56, the first section 66 also being tangential to the second lobe 60. First lobe 56, second lobe 60, and first section 66 may generally define a slideway 70 for spring 20. As shown generally in fig. 5, the projection of the slide 70 may form an acute angle Θ 1 with the base 36 of the archwire slot 16. The slide 70 may be parallel to the support surface 50. Alternatively, the ramps 70 may be adjusted to a slightly smaller angle with the plane including the base 36 than the angle between the support surface 50 and the plane including the base 36.

Additionally, the central portion 64 may include a second section 68 located opposite the first section 66. Second section 68 may be tangential to first lobe 56, but second section 68 may extend in a direction such that the extension of second section 68 intersects (rather than being tangential to) second lobe 60. By further extending the second section 68, the second section 68 may intersect the extension of the first section 66. The angle formed between the first section 66 and the second section 68 may be equal to or less than 60 ° and may depend on the particular tooth to which the bracket 10 is to be attached. By way of example, the angle of second section 68 relative to first section 66 is between about 10 ° and about 30 °, and by further example, the angle of second section 68 relative to first section 66 is between about 19 ° and about 21 °.

With continued reference to fig. 5 and 5A, in one embodiment, the orientation of the first and

second sections

66, 68 of the mid portion 64 forms a restriction or pinch point 72 between the first and

second lobes

56, 60. The pinch point 72 is generally the narrowing of the bore 52 between the first lobe 56 and the second lobe 60. This may include narrowing the aperture 52 to a dimension that is less than the maximum height (or lip-tongue) dimension of both the first lobe 56 and the second lobe 60. By way of illustration only and not limitation, when the first and

second lobes

56 and 60 respectively circumscribe a circular aperture having radii R1 and R2, the perpendicular distance between the nearest opposing portions of the first section 66 and the mid-portion 64 may be measured as the pinch point 72. The perpendicular distance may be less than the diameter of the first lobe 56, less than the diameter of the second lobe 60, or less than both the diameters of the first lobe 56 and the second lobe 60. Further, the dimension may be at least 5% less, or about 10% to about 20% less, than any of the first and

second lobes

56, 60. In one embodiment, radius R2 is less than radius R1 and the size of pinch point 72 is less than twice R2. By way of illustration and not limitation, radius R2 may be about 5% to 15% smaller than radius R1. In an exemplary embodiment, the radius R1 may be about 0.010 inches, the radius R2 may be about 0.009 inches, and the measured pinch point 72 may be about 0.017 inches.

As described above, the aperture 52 may be asymmetrical. This asymmetry may cause pinch point 72 to be offset from the midpoint of the overall length of aperture 52. As shown in fig. 5 and 5A, the pinch point 72 is offset toward the second leaf portion 60. Based solely on this offset, aperture 52 is asymmetric about a plane that forms a perpendicular bisector of the overall length of aperture 52. Furthermore, in embodiments where the first and

second lobes

56, 60 are generally circular, the difference in the respective radial dimensions of the first and

second lobes

56, 60 also creates an asymmetry within the bore 52. The asymmetry within the aperture 52 may produce a unique tactile response in the movement of the slider 14. In particular, as described below, the asymmetry within the aperture 52 may provide the clinician with a unique "click" or "snapping" sound to indicate that the slider 14 has been in the closed position.

With continued reference to fig. 4 and 5, in one embodiment of the invention, the bracket body 12 has at least one shoulder 74, the at least one shoulder 74 being oriented at an angle relative to the slideway 70. In the particular embodiment shown, the bracket body 12 has a mesial shoulder 74 and a distal shoulder 76, the mesial shoulder 74 and the distal shoulder 76 extending generally mesially or distally from the mid-portion 48 and abutting the archwire slot 16. By way of example, the

shoulders

74, 76 both intersect the archwire slot 16 at the slot faces 38 opposite each other. It should be understood, however, that this particular embodiment is not limited to the illustrated configuration of the

shoulders

74, 76.

Referring to fig. 4 and 5, the mesial shoulder 74 and the distal shoulder 76 are angled relative to the slide 70 and generally face in the labial direction. The relative orientation of one or both of the

shoulders

74, 76 may be similar or identical to the orientation of the base surface 36. For example, each

shoulder

74, 76 is generally parallel to the base surface 36 and defines a height H1 (designated in fig. 9D) above the base surface 35. As shown in fig. 1, one or more of the

shoulders

74, 76 may form a contact surface against which the slider 14 rests when the slider 14 is in the closed position and does not positively ligature an archwire within the archwire slot 16, as will be described in detail below.

Referring to fig. 1-4, the bracket body 12 further includes a tool recess 130, the tool recess 130 being formed in a labial position of the archwire slot 16 and extending in a direction generally toward the occlusal side 24. The tool recess 130 provides a pocket or recessed area that is at least partially enclosed from the occlusal side 24 of the bracket body 12 when the slider 14 is in the closed position.The tool recess 130 is configured to receive a tool (not shown) for opening the ligating slide 14. Such as Spin Tek from Ormco^TMA tool or similar tool that may be inserted into the tool recess 130 in a direction aligned with the archwire slot 16. Starting from the insertion direction, the tool is rotated 90 °, the tool is leveraged against the bracket body 12 at a location on or near the slot surface 40, and the slide 14 is then pushed toward the open position.

Further, referring to FIG. 8, in one embodiment, the bracket body 12 may include an occlusal attachment wing (occlualtie wing)134 and a gingival attachment wing (gingival wing) 136. It will be appreciated that the opposing connecting

wings

134, 136 may provide an area into which a clinician may engage a ligature, for example, to provide additional pressure on the slide 14 to maintain the slide 14 against the bracket body 12 and in a closed position during treatment.

Referring to figures 3, 6 and 7, the ligating slide 14 is of a generally U-shaped configuration (as best depicted in figure 7). The ligating slide 14 includes a first leg or proximal portion 80 and a second leg or distal portion 82, the proximal portion 80 and the distal portion 82 defining a slide slot 84 therebetween. The slide slot 84 is sized to slidably engage the slide support 42.

In this regard, the mesial portion 80 and the distal portion 82 may have

shoulders

86, 88, the

shoulders

86, 88 projecting inwardly and generally conforming to the shape of the middle portion 48. The

shoulders

86, 88 may define respective recessed

areas

90, 91, wherein the recessed

areas

90, 91 are configured to slidably receive the

wings

44, 46. The recessed

regions

90, 91 are generally uniform in size along their gingival-occlusal length. In other words. The recessed

areas

90, 91 are not tapered. It should be understood that embodiments of the present invention are not limited to uniform recessed

areas

90, 91 and tapered

wings

44, 46 as their inverse configuration, that is, a combination of a tapered recessed area and a uniform wing, or a tapered recessed area and a tapered wing, are possible and within the scope of the present invention. As shown, the slide slot 84 may thus have a T-shaped configuration that conforms to or corresponds with the shape of the support portion 42 of the bracket body 12.

Referring to fig. 3 and 6, both the proximal central portion 80 and the distal central portion 82 include at least one through hole that receives the resilient member 20. As shown, the mesial portion 80 includes a mesial through-hole 92, while the distal portion 82 includes a distal through-hole 94.

Bores

92, 94 share a common axis 95. As shown, the common axis 95 is located lingual to a plane that includes the labial edge of the archwire slot 16 defined by the ligating slide 14 in the closed position. This orientation may facilitate elastic deformation of the resilient member 20 as the ligating slide 14 is rotated, as described in detail below. It should be understood that the size of the

holes

92 and 94 may be slightly larger than the diameter of the resilient member 20 or the same size as the resilient member 20. For example, the

apertures

92, 94 may be about 0.002 inches, which is larger than the corresponding largest outer dimension of the spring 20. By way of further example, the measured

apertures

92, 94 may be about 10% to about 20% larger than the corresponding outer dimension of the resilient member 20. Alternatively, the

holes

92, 94 may be equal to or smaller than the outer dimension (e.g., outer diameter) of the spring 20. For example, the inner diameter of the

apertures

92, 94 may be about 0.0002 inches less than the outer diameter of the resilient member 20. In this case, the elastic member 20 may be press-fitted into the

respective holes

92 and 94.

As shown in fig. 6 and 7, the proximal central portion 80 and the distal central portion 82 extend from a covering portion 96, wherein the covering portion 96 defines a sliding surface 98 and an outer surface 100. In the exemplary embodiment shown, the outer face 100 forms the surface of the ligating slide 14 closest to the labial side. In one embodiment, the ligating slide 14 includes a mesial ligating portion 102 and a distal ligating portion 104, wherein the mesial ligating portion 102 and the distal ligating portion 104 are formed along portions of the mesial portion 80 and the distal portion 82, respectively, that are closest to the occlusal side. In the exemplary embodiment shown, both the mesial and

distal ligatures

102, 104 include respective guide surfaces 106, 108 and respective

lingual surfaces

110, 112.

When the ligating slide 14 is in the closed position, as shown in figure 8, the lingual surfaces 110,112 are presented to the base surface 36 thereby forming a fourth side of the archwire slot and defining an internal cavity in which the archwire 18 is retained. The

surfaces

110, 112 clearly define the labial boundaries of the archwire slot 16 during orthodontic treatment to capture the archwire within the archwire slot 16. In one embodiment, the

lingual surfaces

110, 112 abut the mesial shoulder 74 and the distal shoulder 76 when the ligating slide 14 is in the closed position.

Further, in one embodiment, the ligating slide 14 includes a tool recess 132, wherein the tool recess 132 is located within the cover 96 between the proximal and distal

central portions

102, 104. The location of the tool recess 132 may be opposite the recess 130 (shown in FIG. 1) such that the tool recess 130 and the tool recess 132 together receive a tool for opening the ligating slide 14. Specifically, a tool (not shown) may be inserted between the ligating slide 14 and the bracket body 12 within the two

slots

130 and 132. A full rotation of 90 from the orientation of the tool inserted into both

slots

130, 132 may cause the ligating slide 14 to move from the closed position toward the open position.

As mentioned above, in one embodiment, the resilient member 20 may be generally tubular with a circular cross-section, as shown in FIG. 3. The cross-section may be continuous, that is, the tubular elastic member 20 may not have grooves or other discontinuities in its sidewall. In this case, unlike the grooved tubular spring pin, the circumference of the elastic member 20 is generally maintained while the elastic member 20 is elastically deformed. Alternatively, as shown in FIG. 3, the elastic member 20a may have a single groove extending longitudinally through its sidewall, wherein the single groove extends generally parallel to the longitudinal axis. The constituent material of spring 20 may be similar to that of spring 20, as described below in commonly owned U.S. patent No. 8,033,824, which is hereby incorporated by reference in its entirety. Unless specifically stated herein, reference to "resilient member 20" refers to resilient member 20 or resilient member 20a shown in fig. 3.

The resilient member 20 is sized to fit within the

apertures

92, 94 and through the aperture 52. In an exemplary embodiment, the elastic member 20 may be composed of a nickel titanium (NiTi) superelastic material. For example, a nickel titanium composition includes about 55 wt% nickel (Ni) and about 45 wt% titanium (Ti) with a small amount of impurities, which is available from NDC of phenmond, california. The mechanical properties of the nickel titanium alloy may include an ultimate tensile strength of greater than about 155ksi, an upper plateau (upper plateau) of greater than about 55ksi, and a lower plateau (lower plateau) of greater than about 25 ksi. The size of the resilient member 20 may vary depending on the size of the bracket itself. In one embodiment, spring 20 is a right circular hollow cylinder having an axis 140 and a diameter of about 0.016 inches, and may be about 0.50 inches to about 0.125 inches in length. The measured wall thickness is from about 0.001 inch to about 0.004 inch, and preferably about 0.002 inch to about 0.003 inch.

In view of the above, and with reference to FIG. 3, the slide 14 is assembled with the bracket body 12 by sliding outwardly from the gingival side 26 of the bracket body 12 in a direction toward the archwire slot 16. The sliding surface 98 is in sliding engagement with at least a portion of the support surface 50 of the slide support portion 42 (best shown in FIG. 3) when the ligating slide 14 is assembled with the bracket body 12.

The T-shaped configuration of the slide support 42, in cooperation with the counter-shaped configuration of the slide slot 84, can inhibit or eliminate the following: in the event of failure of the resilient member 20, the slider 14 accidentally comes off the bracket body 12 in an outward or labial direction. With this configuration, the resilient member 20 may provide a mechanism by which the ligating slide 14 may be secured to the bracket body 12 in both the open position and all closed positions. In a particular embodiment, the resilient member 20 is engaged with the bracket body 12, and more particularly extends through the aperture 52, to secure the slide 14 to the bracket body 12 in both the open position and each of the closed positions.

Referring to FIGS. 3 and 6, after the ligating slide 14 is placed on the bracket body 12, the resilient member 20 is inserted. As shown in fig. 3, spring 20 is positioned within through-hole 94 along axis 95 and through hole 52 into opposing through-hole 92. During assembly, the spring members 20 may be press-fit or slip-fit into the

bores

92, 94 and/or may be secured within the

bores

92, 94 to prevent relative movement therebetween using a variety of processes, including anchoring, tack welding, laser welding, adhesives, or other suitable methods.

Once assembled, as shown in fig. 8, in one embodiment, the tongue surfaces 110, 112 do not extend the full width or vertical distance of the archwire slot 16. In this regard, the bite oriented guide surfaces 106, 108 do not abut the opposing faces of the bracket body 12. For example, the

surfaces

106, 108 do not contact the pocket surface 40. Thus, in this position, there is a gap 114 between the bracket body 12 and the ligating slide 14. The clearance 114 may be deliberate and necessary to ensure that under the load applied by the resilient member 20, the ligating slide 14 is positioned relative to the base 36 so as to always be in contact with one or both of the

shoulders

74, 76.

By forming a gap at this location, it may be more likely or desirable to have the

lingual surfaces

110, 112 of the ligating slide 14 in contact with the

shoulders

74, 76 of the bracket body 12 during treatment. Reducing the number of other points of contact between the ligating slide 14 and the bracket body 12 increases the likelihood of positioning the ligating slide 14 more consistently relative to the bracket body 12. In particular, limiting contact with or providing built-in gaps elsewhere can increase the likelihood of consistent contact between

lingual surfaces

110, 112 and

shoulders

74, 76. Illustratively, the gap 114 may be at least about 0.001 inches, and further illustratively, the measured gap may range from about 0.001 inches to about 0.005 inches. It should be understood, however, that the maximum size of the slot 114 may be limited only by the minimum extension of the ligating slide 14 required to capture the archwire 18 within the archwire slot 16.

With further reference to fig. 7 and 8, another gap or clearance may be established between the slide 14 and the bracket body 12. As shown, in one particular embodiment, each of the mesial portion 80 and distal portion 82 is defined by

surfaces

116, 118, and as shown, when the ligating slide 14 is in the closed position, the

surfaces

116, 118 are opposed from but not in sliding engagement or contact with the bracket body 12. In this regard, a built-in gap 120 is established between the ligating slide 14 and the bracket body 12. Specifically, between the surface 116 and the bracket body 12 at the proximal shoulder 122 and between the surface 118 and the bracket body 12 at the distal shoulder 124 (shown in FIG. 4). By way of example and not limitation, the size of the gap 120 may be similar to the size of the gap 114 between the

surfaces

106, 108 and the slot face 40 as described above. Specifically, the gap 120 may be measured at least about 0.001 inches when the ligating slide 14 is in the closed position, and by way of further example, the gap 120 may be measured from about 0.001 inches to about 0.005 inches.

In a particular embodiment, the slide 14 contacts the bracket body 12 along only two surfaces. One of the contact surfaces is the support surface 50 and the other surface may be one of the

shoulders

74 or 76. When both

shoulders

74, 76 contact the slide 14, there are only three contact surfaces between the slide 14 and the bracket body 12. By providing a limited number of contact points, the position of the slide 14 relative to the bracket body 12 is more consistent.

As noted above, the ligating slide 14 may have a plurality of closed positions; the resilient member 20 may bias the ligating slide 14 in each closed position. For example, the resilient member 20 may bias the slider 14 in the direction of translational movement of the slider 14. With respect to the bias exerted on the ligating slide 14 by the resilient member 20, particular embodiments of the present invention include biased ligating slides that may be similar to the biased ligating slides shown and described in commonly owned U.S. publication No. 2014/0127638, published on day 11/5 2013 and U.S. publication No. 14/205,674, published on day 12/3 2014, which publications are incorporated herein by reference in their entirety.

Biasing the ligating slide 14 may also include biasing in a direction toward the archwire slot 16. Because the ligating slide 14 may be biased by the resilient member 20, tolerance variations in the ligating slide 14 are no longer related to the depth at which the archwire slot 16 is disposed in a generally lip-to-tongue direction. This is because, regardless of the size of the tolerance, the ligating slide 14 may contact the

shoulders

74, 76 of the bracket body 12.

The archwire used during orthodontic treatment has a lip-to-tongue dimension that is the same as or less than the dimension between the base 36 and lingual 110, 112, and the ligating slide 14 may contact and be biased in the proximal 74 and distal 76 shoulders in this position. Accordingly, a tolerance variation that still needs to be considered and monitored during manufacture is the tolerance in positioning the

shoulders

74, 76 relative to the base surface 36 of the archwire slot 16. Advantageously, this reduces the number of tolerances that, when added, ultimately determine the depth of the archwire slot 16 in the generally labial-lingual direction, thereby providing a more consistent fit between the internal cavity formed by the bracket body 12 and ligating slide 14 and the archwire 16. It is believed that rotational control of the teeth can be more consistently maintained and predicted during orthodontic treatment.

Specifically, during use, as shown in the sequence of FIGS. 9A-9D, when the ligating slide 14 is in the open position, the position of the resilient member 20 may be within the first lobe 56 of the aperture 52. A common axis 95 of each of the

bores

92, 94 may be aligned with the axis 58 of the first lobe 56. Depending on the cross-sectional dimensions of the spring 20, the axis 140 of the spring 20 may also be aligned with the axis 58. Generally in this position, since the dimensions of the first lobe 56 and each of the

apertures

92, 94 are generally larger than the dimensions of the resilient member 20, the resilient member 20 is in a relaxed, undeformed state and does not bias the ligating slide 14 in any given direction. However, the elastic member 20 can resist an external force acting on the slider 14 in the direction indicated by the arrow 142 in fig. 9A.

In this regard, the ligating slide 14 may resist inadvertent pushing of an archwire from an open position to a closed position before the archwire is moved out of the archwire slot 16 and a new archwire is inserted into the archwire slot 16. Because middle portion 64 includes segments 68, and segments 68 provide a decreasing gap size that is less than the outer diameter of spring 20, middle portion 64 interferes with movement of spring 20 in the direction indicated by arrow 142. The advantage of interference between the segments 68 and the resilient member 20 is that the distance of movement of the slider 14 is limited before a more significant force is required. Thus, the slider 14 can resist unexpected forces, and the slider 14 is substantially held in the open position until intentionally closed. It should be appreciated that after placing the slide 14 in the open position, the clinician may remove an existing archwire from the archwire slot 16 and insert another archwire into the archwire slot 16 without concern as to whether the ligating slide 14 will accidentally move toward the closed position.

Further to this, the interaction between the resilient member 20 and the aperture 52 may require a deliberate application of force to move the ligating slide 14 to the closed position. Therefore, a minimum threshold force needs to be exerted on the slider 14 to move the slider 14 to the closed position. In one embodiment, the resilient member 20 is moved toward the closed position only when the force exerted on the slider 14 exceeds a minimum threshold force. The force exerted on the slider 14 exceeding the minimum threshold force causes the elastic member 20 to deform elastically. The shape of the central portion 64 of the aperture 52 determines the elastic deformation of the resilient member 20. In this regard, the elastic deformation of the elastic member 20 may be limited to the area in contact with the hole 52. By elastic deformation, the strain generated in the elastic member 20 is completely recovered after the deformation force is removed, and the elastic member 20 is restored to its original shape.

Fig. 9B depicts an exemplary embodiment in which the force exerted on the slider 14 exceeds the minimum threshold force required to move the slider 14 toward the closed position. The slide 14 may be moved toward the closed position when the force applied to the slide 14 is sufficient to cause the resilient member 20 to elastically deform, specifically, the middle portion of the resilient member 20 in contact with the aperture 52 due to the load applied to the ligating slide 14. It will be appreciated that depending on the configuration of the second section 68, a progressively increasing force may be required to continue movement of the slider 14 along the slideway 70 towards the closed position. The shape of the central portion 64 and the properties of the elastic member 20 determine at what rate the force needs to be increased.

As shown in the exemplary embodiment of fig. 9B, the second section 68 is a generally flat surface and is believed to require a generally linearly increasing force on the slider 14, at least for a portion of the opening movement, to deform the resilient member 20 as shown. The elastic member 20 may be deformed in the following manner: allowing it to deform according to a shape defined by the distance between the contact area between the elastic element 20 and the first section 66 and the contact area between the elastic element 20 and the second section 68. As shown, the elastic member 20 may be elastically deformed by a change in the cross-sectional profile of the elastic member 20. This may include a cross-section that varies to a generally oval shape in the contact area between the spring member 20 and the aperture 52. The portion of the spring 14 outside of the aperture 52 may not be significantly elastically deformed to maintain its original cross-sectional profile. For example, the portions of the spring 20 within the

apertures

92, 94 may remain substantially circular. Thus, the elastic deformation of the elastic member 20 is limited to discrete areas where the elastic member 20 is in sliding contact with the hole 52. It should be understood that embodiments of the present invention are not limited to any particular form or shape of the spring member 20. In addition to elastic deformation about the cross-section of the resilient member 20 in contact with the aperture 52, the resilient member may elastically deform along its longitudinal axis in response to loads applied to the ligating slide 14. That is, when the ligating slide 14 is urged toward the closed position and the elastic member 20 encounters the second segment 68, the elastic member 20 is elastically deformed by bending along its longitudinal axis 140. Illustratively, the two ends of spring 20 within mesial and distal through

holes

92, 94 are closer to archwire slot 16 than the middle of contact hole 52. During movement of the ligating slide 14, the resilient member 20 is thus bent along its axis.

Referring to FIG. 9C, the ligating slide 14 is moved closer to the closed position under a force greater than that required to deform the resilient member 20 as shown in FIG. 9B. At the higher forces required to initially move the slider 14 toward the closed position, the force exerted on the slider 14 is sufficient to cause the resilient member 20 to conform to the size of the pinch point 72. At such a magnitude of force, the resilient member 20 is elastically deformed in the contact area with the aperture 52 such that the resilient member 20 can at least partially push past the pinch point 72. As shown, the elastic member 20 can be elastically deformed into an oval cross section. At the pinch point 72, the leading portion 144 of the spring 20 may be located within the second leaf portion 60, while the remaining portion 146 of the spring 20 extends into the central portion 64. The elastic member 20 may be located partially within the second leaf portion 60 and partially within the central portion 64. By way of illustration and not limitation, the force required to move the elastic member 20 to a position where the elastic member 20 partially enters the second leaf 60 may exceed about 0.1kgf (kilogram force), and by way of further illustration, the force may be from about 0.2kgf to about 0.8kgf or from about 0.5kgf to about 0.7kgf, preferably about 0.6 kgf. With continued reference to FIGS. 9A-9C, the amount of force required to overcome the threshold force and/or threshold sliding force as the ligating slide 14 is moved away from the open position may depend on the configuration of the aperture 52. By varying the configuration of the aperture 52, the force is selectively varied. In this regard, the angle of intersection between the second section 68 and the first section 66 may be increased to provide a desired opening force and/or sliding force, as well as the rate at which the force may be increased. In addition, the location of pinch point 72 may be selected to provide a shorter or longer middle portion through which the rate of force increase may be varied. The first section 66 and/or the second section 68 are generally flat in shape to provide a linearly increasing sliding force when the spring 20 is located within the middle portion 64. Alternatively, one or both of the

sections

66, 68 may be contoured or curved (not shown) to provide a variable sliding force. The above-described methods for varying the opening force and/or the sliding force are exemplary.

Referring now to FIG. 9D, once the opening force and/or sliding force reaches or exceeds the force required to move the spring 20 to a position at least partially across the pinch point 72 (as shown in FIG. 9C), the spring 20 will spontaneously slide or move the remaining distance and into the second leaf 60. That is, the guide portion 144 and the remaining portion 146 are automatically completely moved into the second leaf portion 60 without an additional external force. More specifically, once the critical portion of the elastic member 20 enters the second lobe 60, the sliding of the elastic member 20 into the second lobe 60 occurs spontaneously. This movement may be accompanied by a visual and/or tactile "click" or "snapping" sound as the resilient member 20 expands into the second leaf 60. During orthodontic treatment, the clinician may determine by this feature whether the ligating slide 14 has reached its closed position and is maintained in that closed position under the observed positive force.

It is believed that the natural tendency created by the elasticity of the spring member 20 will cause the spring member 20 to return to an undeformed configuration, or at least a less deformed configuration, as compared to the deformed configuration of the spring member 20 in the vicinity of the pinch point 72. Thus, when the critical portion of the resilient member 20 enters the second lobe 60 of the aperture 52, the resilient member 20 may spontaneously release internal elastic energy (by virtue of its deformation). This release causes the elastic member 20 located near the pinch point 72 to slide into and fill the second lobe 60 without applying additional external force. In other words, when an external force is applied to the slider 14 to move the slider 14 to the pinch point 72, only a portion of the elastic member enters the second leaf 60. The elastic member 20 can move the remaining distance and enter the second leaf portion 60, thereby returning to a less elastically deformed configuration or to a configuration without elastic deformation.

In one embodiment, if insufficient force is applied to the spring 20, the spring 20 cannot enter the second leaf portion 60, and the slider 14 can move toward the open position in the absence of external force, as the spring 20 may gradually expand to a larger area of the central portion 64 proximate the first leaf portion 56. Finally, the resilient member 20 may enter the first lobe 56.

In one embodiment, and referring to FIGS. 9D and 10, the ligating slide 14 is shown in a closed position. However, the

holes

92, 94 are not properly aligned with the second lobe 60 of the hole 52. Specifically, the

apertures

92, 94 are offset from the second lobe 60 when the slider 14 is in the closed position. The offset may be in the occlusal-gingival direction. Specifically, the

holes

92, 94 are further from the archwire slot 16 than the second leaf 60.

In one embodiment, the distance between the axis 95 of the

holes

92, 94 and the archwire slot 16 is greater than the distance between the axis 62 of the second leaf portion 60 and the archwire slot when the ligating slide 14 is in the closed position. However, despite the offset relationship, the elastic member 20 may still spontaneously expand into the second leaf portion 60 to release some of the elastic deformation caused by the pinch point 72. That is, less than 100% of the elastic deformation may be released. Thus, as shown in FIG. 10, when the middle of the elastic member 20 is located within the second leaf portion 60, the elastic member 20 is elastically deformed along its axis 140 due to the offset between the axis 62 and the axis 95. It is believed that the lack of alignment between the

apertures

92, 94 and the second leaf portion 60 causes the resilient member 20 to bend or bend (best shown in FIG. 10). Because the resilient member 20 may flex slightly due to the offset of the

axes

62 and 95, either end of the resilient member 20 that is in contact with the ligating slide 14 is biased in a direction toward the archwire slot 16. Thus, the elastic member 20 may retain some elastic deformation in the closed position when the elastic member 20 may spontaneously expand into the second leaf portion 60 to release the stored elastic deformation energy from the forced movement from the open position to the pinch point 72. However, the amount of elastic deformation may be less than that observed at pinch point 72.

As described above, once the slider 14 is in the closed position (fig. 9D), the elastic deformation in the elastic member 20 produces a bias in the slider 14 in the direction of movement of the slider 14, for example, in the direction of the archwire slot 16. In one embodiment, the bias in the resilient member 20 is in the direction of the slide slot 70. In this regard, the direction of offset intersects the plane that includes the base 36 of the archwire slot 16. The bias in the resilient member 20 must be overcome before the slider 14 can move towards the open position. The resilient member 20 provides a more consistent contact between the slider 14 and the bracket body 12 because the applied force must first overcome the bias caused by the resilient deformation of the resilient member 20. For example, the offset may provide more consistent contact between tongue surfaces 110, 112 and

shoulders

74, 76. Advantageously, the depth of the archwire slot 16 in the approximate labial-lingual direction is determined by the location of the

shoulders

74, 76 relative to the base 36 of the archwire slot 16. Other tolerance variations no longer affect the tight fit between the archwire slot cavity and the archwire 18 due to the offset of the

shoulders

74, 76 by the ligating slide 14.

In this configuration, and with reference to FIG. 11, when the ligating slide 14 is in the closed position and the size of the archwire 18 is less than H1, the

lingual surfaces

110, 112 may not contact the archwire 18 as shown. Rather, the

surfaces

110, 112 contact the

shoulders

74, 76. It should be understood that this configuration is observable during treatment, in which case it is more desirable to passively tie the archwire 18. By way of illustration and not limitation, H1 may be about 0.018 inches to about 0.022 inches.

As shown in fig. 11, a void or gap 150 exists between tapered wing 44 and shoulder 86 proximate shoulder 74. The gap 150 may be tapered or wedge-shaped and corresponds to the difference in shape between the tapered wing 44 and the uniform recess 90 (fig. 7). In this further regard, the tapering of the gap 150 may be oriented in the gingival-occlusal direction and opposite the direction of the reduction of the tapered wings 44. At the most occlusal edges of shoulder 86 and wings 44, gap 150 is greatest, while at gingival side 26, gap 150 is smallest. A similar gap (not shown) may be created between the tapered wings 46 and the shoulder 88.

The ligating slide 14 may slidably engage the slide support 42 despite the clearance between the

shoulders

86, 88 and the respective tapered

wings

44, 46. In particular, the cover 96 may slidably engage the support surface 50. As described above, the resilient member 20 may bias the ligating slide 14 in the direction of the archwire slot 16, and particularly in the direction of the base 36. The bias created by the resilient member 20 may forcibly retain the cover 96 on the support surface 50 during at least part of the sliding movement from the open position to the closed position.

As described above, the contact between the support surface 50 and the cover surface 96 is dependent on any angular difference between the support surface 50 and the slide 70. In particular, in one embodiment, a portion of the sliding surface 98 may be slightly displaced from the support surface 50 as the ligating slide 14 contacts one or both of the

shoulders

74, 76. It will be appreciated that this may ensure contact between one or both of

shoulders

74, 76 and tongue-facing

surfaces

110, 112.

As described above, the ligating slide 14 may be slidable relative to the archwire slot 16, and rotatable relative to the archwire slot 16. The ligating slide 14 thus has a plurality of closed positions wherein the archwire 18 is retained in these closed positions. For example, the ligating slide 14 may have a closed position in which one or both of the tongue-facing

surfaces

110, 112 contact the

respective shoulder

74, 76. As described above, the resilient member 20 may bias the ligating slide 14 against one or both of the

shoulders

74, 76.

The ligating slide 14 may be rotated to at least one other closed position. In one embodiment of the present invention, and with reference to FIGS. 11-12A, the ligating slide 14 may be movable away from the base 36 of the archwire slot 16 in a generally outward or labial direction. The outward direction is generally perpendicular to the bottom surface 36 and perpendicular to the slide 70 and/or the support surface 50. In one embodiment, the movement is generally perpendicular to the base surface 36 and/or the chute 70. The rotation is shown by arrow 152 in fig. 12. Further, the rotation opposes the bias of the elastic member 20. That is, the resilient member 20 resists forces acting on the ligating slide 14 to rotate the ligating slide 14.

There are at least two reasons for the rotation of the ligating slide 14 with respect to the archwire slot 16 or further labially. According to one, the rotation may be the result of the archwire 18 within the archwire slot 16 pulling the ligating slide 14 labially. This is depicted in fig. 12. During treatment, if the force tending to pull the archwire 18 away from the archwire slot 16 is greater than the bias exerted by the resilient member 20 on the ligating slide 14, then the ligating slide 14 will rotate relative to the archwire slot 16.

More specifically, when the force exerted by the archwire 18 on the ligating slide 14 reaches a threshold value, the ligating slide 14 will rotate about the point of contact between the ligating slide 14 and the bracket body against the bias exerted by the resilient member 20. The mesial and

distal ligatures

102, 104 may be rotated about the point of contact, causing the

lingual surfaces

110, 112 to lift or separate from the

shoulders

74, 76. For example, the ligating slide 14 may rotate about point 154. As shown, the pivot point 154 is located between the tapered wings 44 and the covering portion 96, and at or near the gingival side 26 of the bracket 10. Although not shown, a similar pivot point may also be created between the tapered wings 46 and the ligating slide 14. Although described as pivot points, it should be understood that these contact locations are the result of two faces contacting each other. Thus, the pivot point is not to be construed restrictively as a point contact. Of course, the contact is between two faces and forms a fulcrum through which loads transferred from the ligating slide 14 to the bracket body 12 pass as the ligating slide 14 is rotated away from the base 36.

During rotation about contact 154, shoulder 86 rotates labially to fill gap 150 (fig. 11). This movement creates a void or gap 156, wherein the void or gap 156 is located between the covering portion 96 that follows the sliding surface 98 and the tapered wings 44. Thus, according to one embodiment, rotation of the ligating slide 14 about the contact point 154 may decrease the gap 150 while simultaneously proportionally increasing the gap 156.

As shown in fig. 12, the gap 156 reaches a maximum when the shoulder 86 contacts the tapered wing 44. Contact at this location may cause the labial-most surface of shoulder 86 to contact the lingual surface of tapered wing 44. Once contact occurs between the shoulder 86 and the bracket body 12 (e.g., on the tapered wings 44, at or near the shoulder 76), rotation stops. Thus, a predetermined amount of angular movement is performed about the pivot point 154 and the ligating slide 14 is no longer rotated. By way of example, the angular movement may be greater than about 5 ° to about 20 °, and further by way of example, the angular movement may be about 10 ° to about 20 °. It should be appreciated that the angular movement exceeds any labial movement associated with tolerance stack-up between the ligating slide 14 and the bracket body 12. The order of magnitude of this type of movement is approximately 5 °.

As shown in FIG. 12, once contact is made, rotation is halted and any additional load placed on the ligating slide 14 at the point of contact 154 and other points of contact between the shoulder 86 and the tapered wing 44 is transferred from the ligating slide 14 to the bracket body 12. Reverse rotation of the ligating slide 14 may also occur.

In this regard, it should be appreciated that as the teeth move closer to their more aesthetically pleasing positions, the archwire 18 may move back toward the base 36 and separate from the

lingual surfaces

110, 112. As shown in fig. 11, as the archwire 18 moves in this direction, the gap 156 decreases while the gap 150 proportionally increases until the

lingual surfaces

110, 112 contact the

respective shoulders

74, 76. The sliding surface 98 may also contact the support surface 50, particularly at or near the gingival-most portion of the tapered wings 44.

The ligating slide 14 may in another case be turned outwards. In one particular embodiment, the bracket 10 may use an archwire having a size greater than H1, thereby requiring outward rotation of the ligating slide 14 similar to that described in the preceding paragraph. The relatively large archwire size may be larger than the pre-set archwire size represented by H1. As noted above, H1 is the lip-tongue dimension from the base surface 36 to the

shoulders

74, 76. In view of the rotational characteristics of the ligating slide 14, and with reference to FIG. 12, when contact occurs at the contact point 154 between the ligating slide 14 and the cover 96, and between the shoulder 86 and the tapered wing 44, as described above, the ligating slide 14 may reach maximum rotational displacement from the archwire slot 16. In this orientation, the

lingual surfaces

110, 112 are displaced from the base surface 36 by a dimension H2 (labeled in fig. 12), wherein the dimension H2 represents the maximum labial-lingual dimension of the archwire that can be inserted into the archwire slot 16. Thus, the archwire to which the bracket 10 can be ligated has a smaller lip-to-tongue dimension than H2.

Illustratively, the size H2 of the archwire 160 is greater than H1, which causes rotation of the ligating slide 14. By way of example and not limitation, when measured at H1 of about 0.020 inches, the relatively large archwire 160 is larger than 0.020 inches. For example, relatively large archwires may have a lip-to-tongue dimension of about 0.022 inches or a lip-to-tongue dimension of about 0.025 inches. When an archwire is used having a lip-tongue dimension greater than H1, the ligating slide 14 may slide over the archwire during sliding movement of the ligating slide 14 between the open and closed positions. In this regard, the guide surfaces 106, 108 of the ligating slide 14 may be rounded to allow the ligating slide 14 to negotiate the archwire 16 during translational movement toward the closed position.

Thus, in the initial stages of treatment where passive ligating of archwires is more desirable, a clinician may employ a small archwire such as the archwire 18 shown in fig. 11. During the initial stages of orthodontic treatment, the relatively small archwire 18 can impart the desired coarse tooth movement (gross tooth movement). During a later stage of orthodontic treatment, the clinician may remove the archwire 18 and insert a relatively large archwire, such as archwire 160, into the archwire slot 16. As shown, the archwire 160 may essentially completely fill the archwire slot 16 to enable the ligating slide 14 to continuously actively ligature the archwire 160. The archwire 160 can provide improved rotational control or other fine positioning control of the teeth typically desired during later stages of orthodontic treatment.

It will be appreciated that the reason the ligating slide 14 is able to positively ligature an archwire 160 in the configuration shown in figure 12 is that the archwire 160 is larger than H1 resulting in elastic deformation of the resilient member 20 which is greater than the elastic deformation of the ligating slide 14 when it contacts the

shoulders

74, 76. As shown in fig. 11A and 12A, the elastic deformation of the elastic member 20 may be in the lip-tongue direction. By way of example and not to be bound by any theory, it is believed that the spring member is elastically deformed longitudinally along longitudinal axis 140, with the opposite ends of spring member 20 within proximal through-hole 92 and distal through-hole 94 flexing labially relative to the portion of spring member 20 within second leaf 60. With respect to FIG. 11A, when the ligating slide 14 is in the closed position and the tongue-facing

surfaces

110, 112 contact the

respective shoulders

74, 76, the resilient member 20 may be slightly curved along its longitudinal axis 140, as shown, with the opposite end of the resilient member 20 positioned labially of the portion of the resilient member 20 that is positioned within the aperture 52.

Referring to fig. 11A and 12A, with the rotation of the ligating slide 14, the elastic member 20 in fig. 12A is elastically deformed to a greater extent than in fig. 11A. Specifically, the opposite end of the elastomeric member 20 will flex further labially such that the axis 95 is further labially offset relative to the axial direction 62 of the second lobe 60 by an amount related to the distance between the

shoulders

74, 76 and the contact location between the

shoulders

86, 88 and the respective tapered

wings

44, 46. It will be appreciated that as the archwire inserted into the archwire slot 16 increases (up to a predetermined maximum value), the level of elastic deformation of the elastomeric member 20 increases, as does the biasing force exerted on each correspondingly larger archwire. This can be illustrated by comparing fig. 11A and 12A, where the archwire 160 is larger in the archwire slot 16 in fig. 12A compared to the archwire 18 in the archwire slot 16 in fig. 11A, and the deformation of the elastomeric member 20 is greater in fig. 12A than in fig. 11A.

During rotation, the elastic member 20 may be elastically deformed in cross section in addition to being elastically deformed in the longitudinal direction. This can best be demonstrated by comparing fig. 11 and 12. When the ligating slide 14 rests on the

shoulders

74, 76, the resilient member 20 may only be slightly deformed in its cross-section. When lifting the ligating slide 14 from the position shown in FIG. 11 toward the fully rotated position shown in FIG. 12, the resilient member 20 is resiliently compressed in its cross-section, wherein the diametrical dimension in the lip-tongue direction is compressed and the diametrical dimension in the occlusal-gingival direction is expanded. As shown in FIG. 12, when the ligating slide 14 reaches its maximum rotational position, the resilient member 20 may deform into an oval or egg-like cross-sectional configuration (as shown exaggerated in FIG. 12). The cross-sectional deformation may be limited to the area immediately adjacent to the

apertures

92, 94 and the aperture 52. When the ligating slide 14 is fully rotated, it will be appreciated that the resilient member 20 produces the maximum bias on the archwire within the archwire slot 16.

While the present invention has been illustrated by a description of various specific embodiments and while these embodiments have been described in considerable detail, it is not the intention of the inventors to restrict or in any way limit the scope of the appended claims to such detail. Accordingly, other features and modifications will be apparent to persons skilled in the art. Whether the various features of the present invention are used alone or in any combination depends on the needs and preferences of the user.

Claims

1. An orthodontic bracket for coupling an archwire with a tooth, the orthodontic bracket comprising:

a bracket body including a hole and an archwire slot;

a ligating slide slidable relative to the archwire slot between an open position and a first closed position, and rotatable relative to the archwire slot to a second closed position, wherein the second closed position is different from the first closed position; and

a resilient member coupled to the ligating slide and slidable within the aperture,

wherein the bracket body includes a slide support defining a pivot point about which the ligating slide rotates from the first closed position to the second closed position, and the slide support has at least one wing extending laterally therefrom, the at least one wing tapering in thickness along its length, the tapering wing defining a first gap between the slide support and a ligating slide in the first closed position, and a second gap between the slide support and a ligating slide in the second closed position.

2. The orthodontic bracket of claim 1, wherein the ligating slide is rotatable to an angle between the first closed position and the second closed position that is greater than about 5 ° up to about 20 °.

3. The orthodontic bracket of claim 1, wherein the ligating slide is rotatable to an angle between the first closed position and the second closed position of about 10 ° to about 20 °.

4. The orthodontic bracket of claim 1, wherein the archwire slot includes opposing slot faces extending from a base face, the ligating slide defining a first height from the base face having a first value in the first closed position, the ligating slide defining a second height from the base face at least 0.002 inch greater than the first value in the second closed position.

5. The orthodontic bracket of claim 1, wherein the ligating slide includes a uniformly sized recess, the wing being positioned within the recess during sliding of the ligating slide.

6. The orthodontic bracket of claim 5, wherein the recess defines a shoulder, the shoulder being in contact with the wing in the second closed position.

7. The orthodontic bracket of claim 6, wherein the first slot is located between the shoulder and the wing.

8. The orthodontic bracket of claim 1, wherein the bracket body includes a support surface and the ligating slide includes a sliding surface, the sliding surface facing the support surface when the ligating slide is in the first closed position, the support surface and the sliding surface contacting at the pivot point when the ligating slide is rotated to the second closed position, an angle of greater than about 5 ° being formed between the support surface and the sliding surface at the pivot point.

9. The orthodontic bracket of claim 8, wherein the pivot point is located at a peripheral edge of the support surface distal from the archwire slot.

10. The orthodontic bracket of claim 1, wherein the resilient member applies a biasing force to the ligating slide in each of the first and second closed positions.

11. The orthodontic bracket of claim 1, wherein the ligating slide does not rotate about the spring.

12. The orthodontic bracket of claim 1, wherein the ligating slide includes a through hole, the resilient member being received into the through hole and extending from the through hole into the hole.

13. An orthodontic bracket for coupling an archwire with a tooth, the orthodontic bracket comprising:

a bracket body including an archwire slot;

a resilient member including opposing ends, each of which is coupled to the ligating slide, and an intermediate portion that slidingly couples the ligating slide to the bracket body,

14. The orthodontic bracket of claim 13, wherein the resilient member is a tubular pin.

15. The orthodontic bracket of claim 13, wherein in the open position, the longitudinal axis of the resilient member extends generally parallel to the archwire slot.

16. The orthodontic bracket of claim 15, wherein the resilient member is curved along the longitudinal axis in at least one of the first and second closed positions.

17. The orthodontic bracket of claim 13, wherein the ligating slide includes a proximal and a distal mesial portion, both extending from the covering portion and defining a slide slot therebetween, the spring being coupled at both ends to the proximal and distal portions, respectively, with the middle portion extending through the slide slot between the proximal and distal portions.

18. An orthodontic bracket for coupling an archwire with a tooth, the orthodontic bracket comprising:

a bracket body including an archwire slot;

a resilient member coupled to the ligating slide and slidable relative to the bracket body, a longitudinal axis of the resilient member extending generally parallel to the archwire slot when the ligating slide is in the open position,

19. The orthodontic bracket of claim 18, wherein the resilient member is a tubular pin.

20. The orthodontic bracket of claim 18, wherein the resilient member is curved along the longitudinal axis in at least the first closed position.

21. The orthodontic bracket of claim 18, wherein the resilient member has opposite ends, each of which is coupled to the ligating slide, and an intermediate portion that slidingly couples the ligating slide to the bracket body.

22. The orthodontic bracket of claim 21, wherein the ligating slide includes a proximal and a distal mesial portion, both extending from the covering portion and defining a slide slot therebetween, the spring member having two ends coupled to the proximal and distal portions, respectively, the middle portion extending across the slide slot between the proximal and distal portions.